Q9XYQ1 · ITPK1_ENTH1
- ProteinInositol-tetrakisphosphate 1-kinase
- GeneITPK1
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids319 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Kinase that can phosphorylate various inositol polyphosphate such as Ins(3,4,5,6)P4 or Ins(1,3,4)P3. Phosphorylates Ins(3,4,5,6)P4 at position 1 to form Ins(1,3,4,5,6)P5. This reaction is thought to have regulatory importance, since Ins(3,4,5,6)P4 is an inhibitor of plasma membrane Ca2+-activated Cl- channels, while Ins(1,3,4,5,6)P5 is not. Also phosphorylates Ins(1,3,4)P3 on O-5 and O-6 to form Ins(1,3,4,6)P4, an essential molecule in the hexakisphosphate (InsP6) pathway. May also act as an isomerase that interconverts the inositol tetrakisphosphate isomers Ins(1,3,4,5)P4 and Ins(1,3,4,6)P4 in the presence of ADP and magnesium.
Catalytic activity
- 1D-myo-inositol 3,4,5,6-tetrakisphosphate + ATP = 1D-myo-inositol 1,3,4,5,6-pentakisphosphate + ADP + H+
Cofactor
Note: Binds 2 magnesium ions per subunit.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Binding site | 17 | 1D-myo-inositol 1,3,4,6-tetrakisphosphate (UniProtKB | ChEBI) | |||
Binding site | 17 | 1D-myo-inositol 1,3,4-trisphosphate (UniProtKB | ChEBI) | |||
Binding site | 57 | 1D-myo-inositol 1,3,4,6-tetrakisphosphate (UniProtKB | ChEBI) | |||
Binding site | 94 | ADP (UniProtKB | ChEBI) | |||
Binding site | 94 | ATP (UniProtKB | ChEBI) | |||
Binding site | 136 | ADP (UniProtKB | ChEBI) | |||
Binding site | 136 | ATP (UniProtKB | ChEBI) | |||
Binding site | 141 | 1D-myo-inositol 1,3,4,6-tetrakisphosphate (UniProtKB | ChEBI) | |||
Binding site | 141 | 1D-myo-inositol 1,3,4-trisphosphate (UniProtKB | ChEBI) | |||
Binding site | 142 | 1D-myo-inositol 1,3,4,6-tetrakisphosphate (UniProtKB | ChEBI) | |||
Binding site | 142 | 1D-myo-inositol 1,3,4-trisphosphate (UniProtKB | ChEBI) | |||
Binding site | 147 | 1D-myo-inositol 1,3,4,6-tetrakisphosphate (UniProtKB | ChEBI) | |||
Binding site | 147 | 1D-myo-inositol 1,3,4-trisphosphate (UniProtKB | ChEBI) | |||
Binding site | 147 | ADP (UniProtKB | ChEBI) | |||
Binding site | 147 | ATP (UniProtKB | ChEBI) | |||
Binding site | 168 | ADP (UniProtKB | ChEBI) | |||
Binding site | 168 | ATP (UniProtKB | ChEBI) | |||
Binding site | 169 | ADP (UniProtKB | ChEBI) | |||
Binding site | 169 | ATP (UniProtKB | ChEBI) | |||
Binding site | 170 | ADP (UniProtKB | ChEBI) | |||
Binding site | 170 | ATP (UniProtKB | ChEBI) | |||
Binding site | 171 | ADP (UniProtKB | ChEBI) | |||
Binding site | 171 | ATP (UniProtKB | ChEBI) | |||
Binding site | 179 | 1D-myo-inositol 1,3,4,6-tetrakisphosphate (UniProtKB | ChEBI) | |||
Binding site | 194 | ADP (UniProtKB | ChEBI) | |||
Binding site | 194 | ATP (UniProtKB | ChEBI) | |||
Binding site | 210 | ADP (UniProtKB | ChEBI) | |||
Binding site | 275 | Mg2+ 1 (UniProtKB | ChEBI) | |||
Binding site | 288 | ADP (UniProtKB | ChEBI) | |||
Binding site | 288 | ATP (UniProtKB | ChEBI) | |||
Binding site | 289 | 1D-myo-inositol 1,3,4,6-tetrakisphosphate (UniProtKB | ChEBI) | |||
Binding site | 289 | ADP (UniProtKB | ChEBI) | |||
Binding site | 289 | ATP (UniProtKB | ChEBI) | |||
Binding site | 289 | Mg2+ 1 (UniProtKB | ChEBI) | |||
Binding site | 289 | Mg2+ 2 (UniProtKB | ChEBI) | |||
Binding site | 291 | 1D-myo-inositol 1,3,4,6-tetrakisphosphate (UniProtKB | ChEBI) | |||
Binding site | 291 | 1D-myo-inositol 1,3,4-trisphosphate (UniProtKB | ChEBI) | |||
Binding site | 291 | ATP (UniProtKB | ChEBI) | |||
Binding site | 291 | Mg2+ 2 (UniProtKB | ChEBI) | |||
Binding site | 295 | 1D-myo-inositol 1,3,4,6-tetrakisphosphate (UniProtKB | ChEBI) | |||
Binding site | 295 | 1D-myo-inositol 1,3,4-trisphosphate (UniProtKB | ChEBI) | |||
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | ATP binding | |
Molecular Function | inositol-1,3,4-trisphosphate 5-kinase activity | |
Molecular Function | inositol-1,3,4-trisphosphate 6-kinase activity | |
Molecular Function | inositol-3,4,5,6-tetrakisphosphate 1-kinase activity | |
Molecular Function | isomerase activity | |
Molecular Function | magnesium ion binding | |
Biological Process | inositol trisphosphate metabolic process | |
Biological Process | phosphorylation |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameInositol-tetrakisphosphate 1-kinase
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Amoebozoa > Evosea > Archamoebae > Mastigamoebida > Entamoebidae > Entamoeba
Accessions
- Primary accessionQ9XYQ1
- Secondary accessions
Proteomes
Organism-specific databases
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Chain | PRO_0000220838 | 1-319 | Inositol-tetrakisphosphate 1-kinase | ||
Interaction
Structure
Sequence
- Sequence statusComplete
- Length319
- Mass (Da)36,480
- Last updated1999-11-01 v1
- MD5 Checksum332E0FDD3F5431CC45E1B6FA15548E86
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AF118848 EMBL· GenBank· DDBJ | AAD22969.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
DS571201 EMBL· GenBank· DDBJ | EAL46318.1 EMBL· GenBank· DDBJ | Genomic DNA |